SIST EN ISO 11439:2013

SLOVENSKI STANDARD
01-december-2013
1DGRPHãþD
SIST EN ISO 11439:2002
3OLQVNHMHNOHQNH9LVRNRWODþQHMHNOHQNH]D]HPHOMVNLSOLQ]DSRJRQPRWRUQLKYR]LO
YJUDMHQHQDYR]LOR,62
Gas cylinders - High pressure cylinders for the on-board storage of natural gas as a fuel
for automotive vehicles (ISO 11439:2013)
Gasflaschen - Hochdruck-Flaschen für die fahrzeuginterne Speicherung von Erdgas als
Treibstoff für Kraftfahrzeuge (ISO 11439:2013)
Bouteilles à gaz - Bouteilles haute pression pour le stockage de gaz naturel utilisé
comme carburant à bord des véhicules automobiles (ISO 11439:2013)
Ta slovenski standard je istoveten z: EN ISO 11439:2013
ICS:
23.020.30 7ODþQHSRVRGHSOLQVNH Pressure vessels, gas
MHNOHQNH cylinders
43.060.40 Sistemi za gorivo Fuel systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 11439
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2013
ICS 23.020.30; 43.060.40 Supersedes EN ISO 11439:2000
English Version
Gas cylinders - High pressure cylinders for the on-board storage
of natural gas as a fuel for automotive vehicles (ISO
11439:2013)
Bouteilles à gaz - Bouteilles haute pression pour le Gasflaschen - Hochdruck-Flaschen für die fahrzeuginterne
stockage de gaz naturel utilisé comme carburant à bord Speicherung von Erdgas als Treibstoff für Kraftfahrzeuge
des véhicules automobiles (ISO 11439:2013) (ISO 11439:2013)
This European Standard was approved by CEN on 18 April 2013.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11439:2013: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 11439:2013) has been prepared by Technical Committee ISO/TC 58 "Gas cylinders"
in collaboration with Technical Committee CEN/TC 23 “Transportable gas cylinders” the secretariat of which is
held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2013, and conflicting national standards shall be withdrawn
at the latest by December 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 11439:2000.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 11439:2013 has been approved by CEN as EN ISO 11439:2013 without any modification.

INTERNATIONAL ISO
STANDARD 11439
Second edition
2013-06-01
Gas cylinders — High pressure
cylinders for the on-board storage of
natural gas as a fuel for automotive
vehicles
Bouteilles à gaz — Bouteilles haute pression pour le stockage de gaz
naturel utilisé comme carburant à bord des véhicules automobiles
Reference number
ISO 11439:2013(E)
©
ISO 2013
ISO 11439:2013(E)
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

ISO 11439:2013(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Service conditions . 4
4.1 General . 4
4.2 Maximum pressures . 4
4.3 Design number of filling cycles . 4
4.4 Temperature range . 4
4.5 Gas composition . 5
4.6 External surfaces . 5
5 Inspection and testing . 6
6 Type approval procedure . 6
6.1 General . 6
6.2 Type approval . 6
6.3 Statement of service . 7
6.4 Design data . 7
6.5 Manufacturing data . 8
6.6 Fracture performance and non-destructive examination (NDE) defect size . 8
6.7 Specification sheet . 8
6.8 Additional supporting data . 8
6.9 Type approval certificate. 8
7 Requirements for type 1 metal cylinders . 8
7.1 General . 8
7.2 Materials . 9
7.3 Design Requirements . 9
7.4 Construction and workmanship .10
7.5 Prototype testing procedure .11
7.6 Batch tests .13
7.7 Tests on every cylinder .15
7.8 Batch acceptance certificate .15
7.9 Failure to meet test requirements .15
8 Requirements for type 2 hoop-wrapped cylinders .16
8.1 General .16
8.2 Materials .16
8.3 Design requirements .17
8.4 Construction and workmanship .18
8.5 Prototype testing procedure .20
8.6 Batch tests on liners and cylinders .22
8.7 Tests on every liner and cylinder .25
8.8 Batch acceptance certificate .26
8.9 Failure to meet test requirements .26
9 Requirements for type 3 fully-wrapped cylinders .27
9.1 General .27
9.2 Materials .27
9.3 Design requirements .28
9.4 Construction and workmanship .29
9.5 Prototype testing procedure .31
9.6 Batch tests on liners and cylinders .35
9.7 Tests on every liner and cylinder .36
ISO 11439:2013(E)
9.8 Batch acceptance certificate .37
9.9 Failure to meet test requirements .37
10 Requirements for type 4 fully-wrapped composite cylinders .38
10.1 General .38
10.2 Materials .38
10.3 Design requirements .38
10.4 Construction and workmanship .39
10.5 Prototype testing procedure .40
10.6 Batch tests .47
10.7 Tests on every cylinder .48
10.8 Batch acceptance certificate .48
10.9 Failure to meet test requirements .49
11 Marking .49
12 Preparation for dispatch .50
Annex A (normative) Test methods and criteria .51
Annex B (normative) Ultrasonic examination .60
Annex C (informative) Non-destructive examination (NDE) defect size by flawed
cylinder cycling .64
Annex D (informative) Report forms .65
Annex E (informative) Standard working pressures .68
Annex F (informative) Verification of stress ratios using strain gauges .69
Annex G (informative) Manufacturer’s instructions for handling, use and inspection
of cylinders .70
iv © ISO 2013 – All rights reserved

ISO 11439:2013(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 11439 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 3,
Cylinder design.
This second edition cancels and replaces the first edition (ISO 11439:2000), which has been technically
revised. In addition to editorial improvements, the principal technical difference between the first and
second editions is the clarification and alteration of the “Change of Design” requirements for the various
cylinder types.
ISO 11439:2013(E)
Introduction
Cylinders for the on-board storage of fuel for natural gas vehicle service are required to be light-weight, at
the same time maintaining or improving on the level of safety currently existing for other pressure vessels.
Owners or users of cylinders designed to this International Standard should note that the cylinders are
designed to operate safely if used in accordance with specified service conditions for a specified finite
service life only. The expiry date is marked on each cylinder and it is the responsibility of owners and
users to ensure that cylinders are not used after that date, and that they are inspected in accordance
with the manufacturer’s instructions.
Users of this International Standard are encouraged to consider the environmental impacts associated
with performing certain tests.
vi © ISO 2013 – All rights reserved

INTERNATIONAL STANDARD ISO 11439:2013(E)
Gas cylinders — High pressure cylinders for the on-board
storage of natural gas as a fuel for automotive vehicles
1 Scope
This International Standard specifies minimum requirements for light-weight refillable gas cylinders
intended only for the on-board storage of high pressure compressed natural gas as a fuel for automotive
vehicles to which the cylinders are to be fixed. The service conditions do not cover external loadings that
can arise from vehicle collisions, etc.
This International Standard covers cylinders of any seamless steel, seamless aluminium alloy or non-
metallic material construction, using any design or method of manufacture suitable for the specified
service conditions. This International Standard does not cover cylinders of stainless steel. Although this
standard uses 200 bar as a reference working pressure, other working pressures can be used.
Cylinders covered by this International Standard are designated Type 1, Type 2, Type 3 and Type 4.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 306, Plastics — Thermoplastic materials — Determination of Vicat softening temperature (VST)
ISO 527-2, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and
extrusion plastics
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7866, Gas cylinders — Refillable seamless aluminium alloy gas cylinders — Design, construction and testing
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 9809-1, Gas cylinders — Refillable seamless steel gas cylinders — Design, construction and testing —
Part 1: Quenched and tempered steel cylinders with tensile strength less than 1 100 MPa
ISO 9809-2, Gas cylinders — Refillable seamless steel gas cylinders — Design, construction and testing —
Part 2: Quenched and tempered steel cylinders with tensile strength greater than or equal to 1 100 MPa
ISO 9809-3, Gas cylinders — Refillable seamless steel gas cylinders — Design, construction and testing —
Part 3: Normalized steel cylinders
ISO 14130, Fibre-reinforced plastic composites — Determination of apparent interlaminar shear strength
by short-beam method
ISO 15403-1, Natural gas — Natural gas for use as a compressed fuel for vehicles — Part 1: Designation
of the quality
ISO 11439:2013(E)
ISO/TR 15403-2, Natural gas — Natural gas for use as a compressed fuel for vehicles — Part 2: Specification
of the quality
ISO 15500-13, Road vehicles — Compressed natural gas (CNG) fuel system components — Part 13: Pressure
relief device (PRD)
ASTM D522-93a, Standard Test Methods for Mandrel Bend Test of Attached Organic Coatings
ASTM D1308-87, Standard Test Method for Effect of Household Chemicals on Clear and Pigmented
Organic Finishes
ASTM D2794-93, Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid
Deformation (Impact)
ASTM D3170-87, Standard Test Method for Chipping Resistance of Coatings
ASTM D3359, Standard Test Methods for Measuring Adhesion by Tape Test
ASTM D3418, Standard Test Method for Transition Temperatures of Polymers by Differential Scanning
Calorimetry
1)
ASTM G154:2006 , Standard Practice for Operating Fluorescent Light Apparatus for UV Exposure of
Nonmetallic Materials
NACE/TM 0177-96, Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking and Stress
Corrosion Cracking in H2S Environments
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
authorized inspection body
authorized inspection body, approved or recognized by the regulatory authority of the user country,
for the supervision of construction and testing of cylinders used for the on-board storage of natural gas
3.2
autofrettage
pressure application procedure used in manufacturing composite cylinders with metal liners, which
strains the liner past its yield point sufficient to cause permanent plastic deformation
3.3
autofrettage pressure
pressure within the overwrapped cylinder at which the required distribution of stresses between the
liner and the overwrap is established
3.4
batch – composite cylinders
group of not more than 200 cylinders plus cylinders for destructive testing, or if greater, one shift of
successive production of cylinders, successively produced from qualified liners having the same size,
design, specified materials of construction and process of manufacture
3.5
batch – metal cylinders/liners
group of not more than 200 cylinders/liners plus cylinders/liners for destructive testing, or if greater,
one shift of successive production of metal cylinders/liners, successively produced having the same
nominal diameter, wall thickness, design, specified material of construction, material cast, process of
manufacture, equipment for manufacture and heat treatment, and conditions of time, temperature and
atmosphere during heat treatment
1) Most recent version is ASTM G154-12a, 2012.
2 © ISO 2013 – All rights reserved

ISO 11439:2013(E)
3.6
batch – non-metallic liners
group of not more than 200 liners plus liners for destructive testing, or if greater, one shift of successive
production of non-metallic liners, successively produced having the same nominal diameter, wall
thickness, design, specified material of construction and process of manufacture
3.7
burst pressure
highest pressure reached in a cylinder during a burst test
3.8
composite cylinder
cylinder made of resin-impregnated continuous filament wound over a metallic or non-metallic liner
3.9
destroyed
cylinder in a state of alteration which makes it physically unusable for its purpose
3.10
finished cylinders
completed cylinders which are ready for use, complete with identification marks and external coating
including integral insulation and/or protection as specified by the manufacturer on the design drawing
for the cylinder
3.11
liner
inner portion of the composite cylinder, comprising of a metallic or non-metallic vessel
3.12
manufacturer
person or organization responsible for the design, fabrication and testing of the cylinders
3.13
overwrap
reinforcement system of filament and resin applied over the liner
3.14
pre-stress
process of applying autofrettage or controlled tension winding
3.15
service life
life, in years, during which the cylinders can be used in accordance with the standard service conditions
3.16
settled pressure
gas pressure when a given settled temperature is reached
3.17
settled temperature
uniform gas temperature in the cylinder after the dissipation of any heat caused by filling
3.18
test pressure
required pressure applied during a pressure test
3.19
type 1 design
an all metal cylinder
ISO 11439:2013(E)
3.20
type 2 design
a hoop wrapped cylinder with a load sharing metal liner and composite reinforcement on the
cylindrical part only
3.21
type 3 design
a fully wrapped cylinder with a load sharing metal liner and composite reinforcement on both the
cylindrical part and dome ends
3.22
type 4 design
a fully wrapped cylinder with a non-load sharing liner and composite reinforcement on both the
cylindrical part and dome ends
3.23
working pressure
settled pressure of a fully filled cylinder at a uniform temperature of 15 °C
4 Service conditions
4.1 General
4.1.1 Standard service conditions
The standard service conditions specified in this clause are provided as the basis for the design,
manufacture, inspection, testing and approval of cylinders that are to be mounted permanently on
vehicles and used to store natural gas at ambient temperatures for use as a fuel on the vehicles.
4.1.2 Service life
The service life for which cylinders are safe shall be specified by the cylinder manufacturer on the basis
of use under service conditions specified herein. The maximum service life shall be 20 years.
4.2 Maximum pressures
This International Standard is based upon a working pressure of 200 bar settled at 15 °C for natural gas
as a fuel with a maximum filling pressure of 260 bar. Other working pressures may be accommodated
by adjusting the pressure by the appropriate factor (ratio); e.g. a 240 bar working pressure system will
require pressures to be multiplied by 1,20. See also Annex E.
Except where pressures have been adjusted in this way, the cylinder shall be designed to be suitable for:
a) a pressure of 200 bar at a settled temperature of 15 °C;
b) a maximum pressure shall not exceed 260 bar, regardless of filling conditions or temperature.
4.3 Design number of filling cycles
Cylinders shall be designed to be filled up to 1 000 times per year of service.
4.4 Temperature range
4.4.1 Settled gas temperature
Settled temperature of gas in cylinders, which may vary from a minimum of –40 °C to a maximum of +65 °C.
4 © ISO 2013 – All rights reserved

ISO 11439:2013(E)
4.4.2 Cylinder temperatures
Cylinders shall be designed for service conditions involving temperatures of between –40 °C and +82 °C.
Cylinder material temperatures over +65 °C are expected to be sufficiently local, or of short enough duration,
that the temperature of gas in the cylinder never exceeds +65 °C, except under the conditions of 4.4.3.
4.4.3 Transient temperatures
Developed gas temperatures in the cylinders during filling and discharge may vary beyond the limits of 4.4.1.
4.5 Gas composition
4.5.1 General
Cylinders shall be designed to tolerate being filled with natural gas meeting the specification
of ISO 15403-1 and ISO/TR 15403-2, and either of dry gas or wet gas as described in 4.5.2 or 4.5.3,
respectively. Methanol and/or glycol shall not be deliberately added to the natural gas.
NOTE Where it is suspected that wet-gas conditions may exist, it has been found that a minimum of 1 mg of
compressor oil per kg of gas has prevented the corrosion of steel cylinders.
4.5.2 Dry gas
Water vapour shall be limited to less than 32 mg/m (i.e. a pressure dewpoint of –9 °C at 200 bar).
Constituent maximum limits shall be:
Hydrogen sulfide and other soluble sulfides 23 mg/m
Oxygen 1 % (volume fraction)
Hydrogen, when cylinders are manufactured from a steel with an ultimate 2 % (volume fraction)
tensile strength exceeding 950 MPa
4.5.3 Wet gas
For gas that has a higher water content than that of dry gas, constituent limits shall be:
Hydrogen sulfide and other soluble sulfides 23 mg/m maximum
Oxygen 1 % (volume fraction) maximum
Carbon dioxide 3 % (volume fraction) maximum
Hydrogen 0,1 % (volume fraction) maximum
Compressor oil 1 mg/kg natural gas minimum (see Note 4.5.1)
4.6 External surfaces
It is not necessary for cylinders to be designed for continuous exposure to mechanical or chemical
attack (e.g. leakage from cargo that may be carried on vehicles or severe abrasion damage from road
conditions). However, cylinder external surfaces shall be designed to withstand inadvertent exposure
to mechanical or chemical attack consistent with their installation being carried out in accordance with
the instructions to be provided with the cylinder.
Mechanical or chemical attack may result from environments such as:
a) water, either by intermittent immersion or road spray;
ISO 11439:2013(E)
b) salt, due to the operation of the vehicle near the ocean or where ice-melting salt is used;
c) ultraviolet radiation from sunlight;
d) impact of gravel;
e) solvents, acids and alkalis, fertilizers;
f) automotive fluids, including petrol, hydraulic fluids, battery acid, glycol and oils;
g) exhaust gases.
5 Inspection and testing
Evaluation of conformity can be carried out in accordance with the relevant regulations recognized by
the country(ies) where the cylinders are intended to be used.
To ensure that cylinders are in conformance to this International Standard, they shall be subject
to inspection and testing in accordance with Clauses 7, 8, 9, or 10 and Annex A as appropriate to the
construction. This shall be carried out by an authorized inspection body, hereafter referred to as “the
Inspector”, recognized in the countries of use. The Inspector shall be competent for inspection of cylinders.
6 Type approval procedure
6.1 General
Type approval consists of two parts:
a) design approval, comprising submission of information by the manufacturer to the Inspector, as
detailed in 6.3.
b) prototype testing, comprising testing carried out under the supervision of the Inspector. The
cylinder material, design, manufacture and examination shall be proved to be adequate for their
intended service by meeting the requirements of the prototype tests specified in 7.5, 8.5, 9.5 or 10.5,
and Annex A, as appropriate for the particular cylinder design.
The test data shall also document the dimensions, wall thicknesses and weights of each of the test cylinders.
6.2 Type approval
Cylinder designs shall be approved by the Inspector. Information shall be submitted by the manufacturer
with a request to the Inspector for approval, and shall include:
a) statement of service, in accordance with 6.3;
b) design data, in accordance with 6.4;
c) manufacturing data, in accordance with 6.5;
d) fracture performance and NDE defect size, in accordance with 6.6;
e) specification sheet, in accordance with 6.7;
f) additional supporting data, in accordance with 6.8.
6 © ISO 2013 – All rights reserved

ISO 11439:2013(E)
6.3 Statement of service
The purpose of the statement of service is to guide users and installers of cylinders as well as to inform
the Inspector. The statement of service shall include:
a) a statement that the cylinder design is suitable for use in the service conditions defined in Clause 4
for the service life of the cylinder;
b) a statement of the service life;
c) the minimum periodic inspection requirements;
d) a specification for the pressure relief devices, and insulation if provided;
e) a specification for the support methods, protective coatings and any other items required but
not provided;
f) a description of the cylinder design;
g) any other information and instructions necessary to ensure the safe use and inspection of the cylinder.
6.4 Design data
6.4.1 Drawings
Drawings shall include, as a minimum:
a) title, manufacturer, reference number, date of issue, and revision numbers with dates of issue if
applicable;
b) reference to this International Standard and the cylinder type;
c) all cylinder dimensions complete with tolerances, including details of end closure shapes, openings,
and neck threads;
d) water capacity and mass (including any permanent attachments), complete with tolerance, of cylinders;
e) material specifications, mechanical properties (including tolerances where applicable) and, for
metal cylinders or metal liners, the specified hardness range;
f) other data such as, working pressure, autofrettage pressure, test pressure, minimum design burst
pressure, design life;
g) details of the fire protection system and of any exterior protective coating.
6.4.2 Stress analysis report
A finite element stress analysis or other stress analysis shall be carried out. A table summarizing the
calculated stresses shall be provided.
6.4.3 Material property data
A description of the materials and tolerances of the material properties used in the design shall be
provided. Test data shall also be presented characterizing the mechanical properties and the suitability
of the materials for service under the conditions specified in Clause 4.
ISO 11439:2013(E)
6.4.4 Fire protection
The arrangement of pressure relief devices, and insulation if provided, that will protect the cylinder
from sudden rupture when exposed to the fire conditions in A.15 shall be specified. Test data shall
substantiate the effectiveness of the specified fire protection system.
NOTE A manufacturer may specify alternative PRD locations for specific vehicle installations.
6.5 Manufacturing data
Details of fabrication processes, non-destructive examinations, production tests and batch tests shall be
provided. Production processes such as heat treatment, end forming, resin-mix ratio, filament tension
and speed for controlled tension winding, curing times and temperatures, and autofrettage procedures
shall be specified.
Surface finish, thread details, acceptance criteria for ultrasonic examination (or equivalent), and
maximum lot sizes for batch tests shall also be specified.
6.6 Fracture performance and non-destructive examination (NDE) defect size
The manufacturer shall specify the maximum defect size for non-destructive examination that will
ensure leak before break (LBB) fracture performance, and will prevent failure by leakage or rupture of
the cylinder during its service life. The maximum defect size shall be established by a method suitable
to the design.
NOTE An example of a suitable method is given in Annex C.
6.7 Specification sheet
A summary of the documents providing the information required in 6.2 shall be listed on a specification
sheet for each cylinder design. The title, reference number, revision numbers and dates of original issue
and version issues of each document shall be given. All documents shall be signed or initialled by the issuer.
6.8 Additional supporting data
Additional data that would support the application may be provided.
6.9 Type approval certificate
If the results of the type approval according to 6.1 and the prototype testing according to 7.5, 8.5, 9.5 or
10.5, and Annex A, as appropriate to the particular cylinder design, are satisfactory, the Inspector shall
issue a test type approval certificate.
NOTE An example of a type approval certificate is given in Annex D.
7 Requirements for type 1 metal cylinders
7.1 General
This International Standard does not provide design formulae, nor list permissible stresses or strains,
but requires the adequacy of the design to be established by appropriate calculations and demonstrated
by testing to show that cylinders shall pass the materials, design qualification, production and batch
tests specified.
The design shall ensure a “leak-before-break” failure mode during normal service.
8 © ISO 2013 – All rights reserved

ISO 11439:2013(E)
7.2 Materials
7.2.1 General requirements
Materials used shall be suitable for the service conditions specified in Clause 4. The design shall not have
incompatible materials in contact with each other.
7.2.2 Controls on chemical composition
7.2.2.1 Steel
Steels shall be aluminium- and/or silicon-killed. The chemical composition of all steels shall be declared
and defined at least by:
a) the carbon, manganese, aluminium and silicon contents in all cases;
b) the chromium, nickel, molybdenum, boron and vanadium contents, and that of any other alloying
elements intentionally added.
The sulfur and phosphorus content in the cast analysis shall not exceed the values given in Table 1.
Table 1 — Maximum sulfur and phosphorus limits
sulfur 0,010 % by mass
phosphorus 0,020 % by mass
sulfur + phosphorus 0,025 % by mass
7.2.2.2 Aluminium
Aluminium alloys may be used to produce cylinders provided that they meet all requirements of this
International Standard and have maximum lead and bismuth contents not exceeding 0,003 %.
2)
NOTE A list of registered alloys is maintained by the Aluminium Association Inc. and can be found under
the “International Registration Records”, entitled “International Alloy Designations and Chemical Composition
Limits for Wrought Aluminium and Wrought Aluminium Alloys”.
7.3 Design Requirements
7.3.1 Test pressure
The minimum test pressure used in manufacture shall be 1,5 times working pressure.
7.3.2 Burst pressure
The minimum burst pressure shall be not less than 2,25 times working pressure.
7.3.3 Stress analysis
The stresses in the cylinder shall be calculated for the working pressure, test pressure and design burst
pressure. The calculations shall use suitable analysis to establish stress distributions to justify the
minimum design wall thicknesses.
2) Aluminum Association Inc., 900 19th Street N.W., Washington D.C., 20006-2168, USA.
...